• Journal of the Korean Geotechnical Society
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• v.31 no.4
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• pp.45-55
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• 2015

The stability of the adjcent structures or slopes under blasting is typically evaluated using an empirical vibration attenuation curve or dynamic numerical analysis. To perform a dynamic analysis, it is necessary to determine the blast load and the damping ratio of rock mass. Various empirical methods have been proposed for the blast load. However, a study on representative values of damping ratio of a rock mass has not yet been performed. Therefore, the damping ratio was either ignored or selected without a clear basis in performing a blast analysis. Selection of the dampring ratio for the rock mass is very difficult because the vibration propagation is influenced by the layout and properties of the rock joints. Besides, the vibration induced by blasting is propagated spherically, whereas plane waves are generated by an earthquake. Since the geometrical spreading causes additional attenuation, the damping ratio should be adjusted in the case of a 2D plane strain analysis. In this study, we proposed equivalent damping ratios for use in continuum 2D plane strain analyses. To this end, we performed 2D dynamic analyses for a wide range of rock stiffness and investigated the characteristics of blast vibration propagation. Based on numerical simulations, a correlation between the attenuation equation, shear wave velocity, and equivalent damping ratio of rock mass is presented. This novel approach is the first attempt to select the damping ratio from an attenuation relationship. The proposed chart is easy to be used and can be applied in practice.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.455-459
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• 2017

Norovirus (NoV) is the most common cause of acute gastroenteritis in all age groups worldwide. In this study, prevalence of asymptomatic norovirus infection was investigated in food handler being employed at food catering facilities in South Korea. A total of 2,729 fecal specimens from asymptomatic food handlers were analyzed, and 1.06% of food handlers (29/2,729) had asymptomatic NoV infection. Of these, 17.2% (5/29) were positive for NoV GI and 82.7% (24/29) were positive for NoV GII. Especially, sequencing and phylogenetic analysis showed that GII-4 was the most prevalent genotype and a large number of asymptomatic food handlers were infested with norovirus GII-4 strains. The results of this study show that asymptomatic food handlers may be potential transmission sources for NoV infection. These results emphasize the need for training of food catering employees about norovirus prevention. Asymptomatic norovirus infection should receive more attention.

• The Journal of the Convergence on Culture Technology
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• v.7 no.2
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• pp.261-267
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• 2021

The enlightenment project raised in both Korea and China during the modern period worked as a part of the patriotic enlightenment movement against the imperial powers. Among them, "boy" appeared as the subject of enlightenment, and "sea" appeared as a medium. Specifically, through "Boy Discourse," Liang Qi Chao ultimately envisioned a nation for "subjects", and Choi Nam-seon also seeked to overcome the national crisis as "New Korea" and join the ranks of powerful nations. Liang Qiqiao proposes the concept of a "Boy Nation" and an "Old Nation" through boy discourse, and wishing for the development of the "Boy Nation" through "proficiency training". Choi Nam-seon also recognized that the future of the nation depends on "boys", influenced by Liang Qi-qiao's discourse on boys, and argues that Choseon should cultivate skills to become a "Boy Nation". In addition, Liang Qi-chao and Choi Nam-seon actively spread the "boy discourse" through the creation of poetry. Liang Qi Chao introduced the world's geography and history through poetries related to the sea, while at the same time inspiring a sense of challenge to recognize and pioneer the sea as a pathway that connects the world in a broad sense. Namseon Choi also created a poem that directly linked "the sea" and the "boy" to promote the "adventure at sea" and "the progressive spirit of the sea and the boy".

• (The) Research of the performance art and culture
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• no.37
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• pp.327-363
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• 2018

Bhutan's mask dance drama, Cham is performed in the festival of Tshechu. Originating from the 17th century, Tschechu is a religious ritual as well as a traditional festival held to commemorate the birth of Padmasambhava, who spread Buddhism in the kingdom of Bhutan. Bhutanese Cham and Tibetan Cham share similar traits in their content of , , and in their characters of Pawo and Pamo. Meanwhile, , , , , , , , are distinctive performances of Bhutanese cham. Moreover, the clown character Atsara in Bhutanese cham is a character that does not appear in the Tibetan Cham. Atsara, a humorous character, can be identified by its use of a long phallus ornament on the head or by a distorted face mask with a phallus in its hand. Bhutanese Cham, originally from Tibet, is a religious mask dance drama handed down in Lamaism temples. In later generations, new performances reflective of Bhutan's history, myth, legends, and religion were added in large amount. Thus, the Cham of Bhutan now has very independent and characteristic aspects.

• Korean Journal of Heritage: History & Science
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• v.47 no.3
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• pp.160-171
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• 2014

The provision of support for the art of making these items needs to be considered with the focus on the following factors: the local situation of the areas where such traditional handicrafts are still made, the craftspeople involved in their production, and their communities. So far, discussion about how to reinvigorate traditional handicrafts, including those mentioned above, has been concentrated on the measures taken to promote them as part of the handicrafts industry and the allocation of the government's budget for important intangible cultural heritages. The government runs a traditional handicrafts management system and provides financial support for the craftspeople and spaces for exhibiting their work. This form of support has led to systematic management of traditional handicrafts and heightened public interest in cultural heritage, as well as publicizing the country's traditional crafts, but has made little progress in the following areas: the fostering of young people willing to learn traditional skills, diversification of the types of skills to be maintained, or establishment of the networks of collaboration among the craftspeople. The most important aspect among the efforts mentioned above is to maintain cultural traditions that are unique to each region by encouraging local craftspeople to engage in their work with a solid sense of pride backed up by financial support. This study was carried out in connection with the need to reinvigorate the art of making tanggeon (horsehair crown), manggeon (horsehair headband), and gat (black horsehair hat), which few people wear as they are used only for ornamental purposes nowadays. This study examined the circumstances surrounding the artisans engaged in the production of horsehair handicrafts prior to their designation as a cultural heritage, and the changes that occurred in the local communities associated with their production after the designation, in order to assess the status of inheritance of this tradition.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.131-142
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• 2020

Chrysnathemum stunt viroid (CSVd), a small, single-stranded, infectious RNA, has caused a severe problem in chrysanthemum in the world. In Korea, since CSVd was firstly observed in 1997, the disease has been spread throughout the whole country rapidly. In spite of the seriousness, few methods for control of CSVd have been known without prevention. The use of resistant cultivars is one of the most efficient approaches for overcoming CSVd disease in chrysanthemum cultivation. This study was carried out to identify chrysanthemum genetic resources for the resistance to chrysanthemum stunt viroid (CSVd). A total of 192 commercial cultivars including 167 spray and 25 standard chrysanthemum were screened with CSVd through grafting inoculation method. In most of the inoculated cultivars, typical disease symptoms, stunting of plant height, reduced flower size, and flower color bleaching, were induced. Several cultivars, however, were symptomless or showed delay in symptom expression. Of 192 chrysanthemum cultivars, two cultivars with less than 5% of the average reduction rate of plant height, 'Chiwerel' and 'Jeongheungdaesin', were rated as resistant. And six cultivars less than 20% inculding 'Inga' were rated as moderate resistant. The remaining 184 cultivars with a high level of reduction were rated as susceptible. We expect that these genetic resources can be used in crossbreeding programs for developing CSVd resistant cultivars of chrysanthemum.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.607-622
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• 2022

The Spring Festival is the most important traditional celebration in China, and it has the important value of condensing the national spirit and emotion, inheriting traditional culture and customs, and showing the development and changes of contemporary China. As a kind of TV performance art and cultural media carrier, The Spring Festival Gala of China Media Group (C.M.G) has been broadcast for 40 years and has exerted a great influence on the development of China's media industry. These days, China's TV performing arts and Chinese media that represented by The Spring Festival Gala, are not only the main front of domestic propaganda, but also shoulder the historical responsibility of building the image of a great country and exporting Chinese remarkable culture to the outside world. Therefore this study had summarizes The Spring Festival Gala change trend in the past 40 years focus on the theme of The Spring Celebration, the development of multimedia, and the interaction between society and culture in different periods of Chinese social background, and also analyzes the current problems of the Spring Festival by combining relevant data and specific cases. so as to make forward-looking suggestions for the and how the Chinese media industry can further develop towards globalization.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.5-12
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• 2009

As rock bolts become one of the main support systems in tunnels and underground structures, the integrity of the rock bolts affects the safety of these structures. The purpose of this study is the evaluation of rock bolt integrity using wavelet transforms of the guided ultrasonic waves by using transmission test in the field. After several rock bolts with various defect ratios are embedded into a large scale concrete block and rock mass, guided waves are generated by a piezo disk element and measured by an acoustic emission (AE) sensor. The captured signals are analyzed in the time-frequency domain using the wavelet transform based on a Gabor wavelet. Peak values in the time-frequency domain represent the interval of travel time of each echo. The energy velocities of the guided waves increase with an increase in the defect ratio. The suitable curing time for the evergy velocity analysis is proposed by the laboratory test, and in-situ tests are performed in two tunnelling sites to verify the applicability of rock bolt integrity tests performed after proposed curing time. This study proves that time-frequency domain analysis is an effective tool for the evaluation of the rock bolt integrity.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.102-108
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• 2024

This study was performed to establish the epidemiological features of a food poisoning outbreak that occurred in the cafeteria of a company in Chungcheongnam-do Province, Korea, in October 2020, and to recommend measures to prevent similar outbreaks. Twenty-one patients with acute gastroenteritis, three food handlers, seven cooking utensils, and 12 preserved food samples were subjected to viral and bacterial analyses based on procedures described in the "Manual for Detection of Foodborne Pathogens at Outbreaks". Among 135 individuals who had been served the meals, 21 (15.6%) showed symptoms of nausea and vomiting within an hour of consuming the food. Bacillus cereus were isolated from 11 (52.4%) of the 21 patients, one food service employee, one item of cooking ware, and 12 preserved food samples. In addition, we confirmed the toxin genes CER, nheA, and entFM from the isolated B. cereus strains. Pulsed-field gel electrophoresis results indicated that all of the isolated B. cereus strains were closely related, with the exception of strains obtained from one patient and one sample of preserved food. These findings provide evidence to indicate that the isolated B. cereus originated from preserved foods and an unhygienic eating environment. This outbreak highlights that the provision of food in non-commercial food systems must be thoroughly managed. In addition, it emphasizes the necessity for the correct and timely identification of causal pathogens for tracing the cause of food poisoning outbreaks, and the need to preserve food under appropriate conditions. To prevent similar cases of food poisoning, it is necessary to investigate cases based on an epidemiological approach and share the findings.

• Journal of Life Science
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• v.30 no.3
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• pp.313-319
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• 2020

Recently, cattle epidemic diseases are caused by a pathogen such as a virus or bacterium. Such diseases can spread through various pathways, such as feed intake, respiration, and contact between livestock. Diagnosis based on the ELISA (Enzyme-linked immunosorbent assay) and PCR (Polymerase chain reaction) methods has limitations because these traditional diagnostic methods are time consuming assays that require multiple steps and dedicated equipment. In this review, we propose the use of the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) Cas system based on DNA and RNA levels for early point-of-care diagnosis in cattle. In the CRISPR/Cas system, Cas effectors are classified into two classes and six subtypes. The Cas effectors included in class 2 are typically Cas9 in type II, Cas12 in type V (Cas12a and Cas12b) and Cas13 in type VI (Cas13a and Cas13b). The CRISPR/Cas system uses reporter molecules that are attached to the ssDNA strands. When the Cas enzyme cuts the ssDNA, these reporters either fluoresce or change color, indicating the presence of a specific disease marker. There are several steps in the development of a CRISPR/Cas system. The first is to select the Cas enzyme depending on DNA or RNA from pathogens (viruses or bacteria). Based on that, the next step is to integrate the optimal amplification, transducing method, and signal reporter. The CRISPR/Cas system is a powerful diagnostic tool using a gene-editing method, which is faster, better, and cheaper than traditional methods. This system could be used for early diagnosis of epidemic cattle diseases and help to control their spread.